<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>模态框</title>
</head>
<body>
    <button>弹出模态框</button>

    <div class="modal-wrap"></div>
    <div class="header">模态框标题
        <span class="btn-close"></span>
    </div>

    <script>
        const butOpen = document.getElementById
    </script>
    
</body>
</html>